JP2003172633A - Integrated direction sensor - Google Patents

Abstract

(57) [Summary] [Problem] To provide a small-sized integrated azimuth sensor capable of azimuth detection and attitude detection and capable of being mounted on a portable device. The present invention provides an acceleration sensor for detecting gravitational acceleration, a magnetic sensor for detecting terrestrial magnetism, and an arithmetic processing unit for arithmetically processing acceleration information from the acceleration sensor and magnetic information from the magnetic sensor. It is provided with. The acceleration sensor 3 includes a support body 8 fixed to the glass table 5, a weight 7, and beams 31 to 38 for movably supporting the weight 7 on the support 8. The magnetic sensor 4 and the arithmetic processing unit 6 are respectively arranged at predetermined positions on the weight unit 7 constituting the acceleration sensor 3.
As described above, according to the present invention, the magnetic sensor 4 and the arithmetic processing unit 6 are incorporated in a part of the weight unit 7 constituting the acceleration sensor 3, so that the overall size is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite sensor in which a magnetic sensor and an acceleration sensor are mounted together, and in particular, it is small enough to be built in a portable device and has an attitude and orientation of the portable device, that is, an angle with respect to gravity and earth magnetism. The present invention relates to an integrated azimuth sensor capable of detecting the.

[0002]

2. Description of the Related Art Conventionally, as a posture detecting device for detecting a posture, one disclosed in Japanese Patent Laid-Open No. 10-185608 is known. This attitude detecting device is composed of a magnetic sensor capable of detecting biaxial magnetic flux, an inclination sensor using a biaxial acceleration sensor, and an arithmetic circuit. The magnetic sensor, the tilt sensor, and the arithmetic circuit are formed on independent substrates, and these independent substrates are arranged on different substrates. The magnetic sensor described above can detect a geomagnetic component in a direction parallel (orthogonal 2) to the sensor surface.

However, except for some areas near the equator,
Since the direction of the geomagnetic vector is not horizontal with respect to the ground surface and there is a depression angle, it is impossible to detect an accurate azimuth when the device is used in a tilted state. In order to eliminate this inconvenience, it is possible to detect the tilt of the device by the tilt sensor and correct the output signal of the magnetic sensor to accurately detect the geomagnetic direction. On the other hand, as a small-sized acceleration sensor having a direction measuring function, Japanese Patent Application Laid-Open No.
The one described in JP-A-160349 is known. This is on the same substrate that constitutes the acceleration sensor,
A Hall element for detecting a magnetic field perpendicular to the substrate surface is provided. That is, a weight portion made of a silicon chip is movably arranged on a pedestal made of glass to serve as an acceleration sensor, and a hall element is arranged on the weight portion.

The attitude detecting device described in Japanese Patent Laid-Open No. 10-185608 uses a fluxgate sensor as a magnetic sensor. In addition, JP-A-11-16034
The device disclosed in Japanese Patent No. 9 uses a Hall element made of indium antimony, gallium arsenide or the like as a magnetic sensor.

[0005]

However, JP-A-10-
In the attitude detection device described in Japanese Patent No. 185608, the magnetic sensor and the inclination angle sensor are formed on independent substrates,
Each independent board is assembled. Therefore, when the attitude detection device is mounted on a small device such as a mobile device, there is a disadvantage that it is too large. By the way, the fluxgate sensor described in Japanese Patent Laid-Open No. 10-185608 is a (1-axis or 2-axis) magnetic sensor that detects a magnetic component in a direction parallel to the sensor surface, and a magnetic force in a direction perpendicular to the sensor surface. The component cannot be detected.

In the above publication, the output of the tilt sensor is used to perform a correction calculation based on the biaxial geomagnetic component of the fluxgate sensor, and the method is roughly divided into 2 as a method for obtaining the geomagnetic direction, that is, the horizontal component of the geomagnetic field. The correct correction calculation method is described. In the first half, the vertical direction component of the geomagnetism is regarded as 0 and the correction calculation is performed. However,
Except for the extremely limited area near the equator, there is a vertical component in the geomagnetism, and the depression angle of the geomagnetism is usually 3 in Japan.
It is known to range from 5 degrees to 60 degrees. Therefore, when the correction method in the first half, which assumes that the vertical component of the geomagnetism is 0, is applied, only a result different from the direction of the horizontal component of the geomagnetism that should be originally obtained, that is, the geomagnetic direction is obtained.

On the other hand, in the latter half, correction calculation is performed by regarding the vertical component of the geomagnetism as a constant value. Since the vertical component of the earth's magnetism varies from place to place, this method requires the complicated operation of standing the attitude detector upright first and measuring the vertical component of the earth's magnetism every time the place to be measured changes. There is. Further, this method has a problem that the attitude detection device is largely tilted, and a large measurement error occurs in the measurement result when the surface of the flux gate sensor is close to vertical.

In detecting the tilt angle, Japanese Laid-Open Patent Publication No. 10-1856.
It can be detected by a biaxial acceleration sensor as described in JP-A-08. However, in this case, since the acceleration sensor of each axis detects the cosine component of the gravitational acceleration, an error is likely to occur when the inclination angle becomes large. Therefore, similarly to the case of geomagnetism, it is necessary to accurately detect the acceleration component in the detection direction, and it is necessary to compensate for temperature characteristics such as sensitivity. Since the geomagnetic direction is the direction of the geomagnetic vector in the horizontal direction, it goes without saying that at least a biaxial magnetic sensor is required even if the conditions for use, such as the inclination, are limited to horizontal.

In the one disclosed in Japanese Patent Application Laid-Open No. 11-160349, a Hall element made of indium antimony, gallium arsenide, etc. is provided on a weight portion constituting an acceleration sensor. In general, since the Hall element can detect only the magnetic flux density in the direction perpendicular to the sensing surface, that is, in the uniaxial direction, it is impossible to know the accurate azimuth with such a configuration. Further, there is no description in the above publication about a method of detecting magnetic flux densities of two or more axes using a Hall element, and even if the output of the tilt sensor is used, the direction of the horizontal component of the geomagnetism is corrected and calculated. I can't.

Therefore, in view of the above points, an object of the present invention is to provide a small integrated azimuth sensor which can detect the azimuth and the attitude and can be mounted on a portable device.

[0011]

In order to solve the above problems and achieve the object of the present invention, the inventions described in claims 1 to 12 are configured as follows. That is, the invention according to claim 1 is a magnetic sensor of at least three axes for detecting geomagnetism, an acceleration sensor of two or more axes for detecting gravitational acceleration, an output signal from the magnetic sensor and an output from the acceleration sensor. A signal processing unit for processing a signal, wherein the acceleration sensor includes a support body made of a silicon substrate and fixed, a weight section made of the silicon substrate, and a beam for movably supporting the weight section on the support body. At least, the magnetic sensor and the signal processing unit,
It is characterized in that it is arranged either on the support or on the weight portion, or on the support and on the weight portion in a dispersed manner.

According to a second aspect of the present invention, in the integrated azimuth sensor according to the first aspect, the magnetic sensor is disposed at a predetermined position on the support or the weight portion, and the support or the support is provided. A magnetic flux concentrating plate that converges magnetic flux in a direction along the surface of the weight portion, and a surface side of the support or the weight portion, which is arranged near a predetermined end portion of the magnetic flux concentrating plate, and each end portion thereof. And at least three Hall elements for respectively detecting magnetic fluxes spreading in the vicinity of.

According to a third aspect of the present invention, in the integrated azimuth sensor according to the second aspect, the magnetic sensor is arranged at a predetermined position on the support or the weight portion. One magnetic flux concentrator plate and a plurality of second magnetic flux concentrator plates on the support or on the weight portion and arranged at predetermined intervals in an outer peripheral direction around the first magnetic flux concentrator plate; A plurality of magnetic fluxes that are located on the surface side of the support or the weight portion and that are adjacent to the first magnetic flux concentrator plate and the second magnetic flux concentrator plates are adjacent to each other, and that detect a magnetic flux spreading in the vicinity thereof. And a Hall element of.

According to a fourth aspect of the present invention, in the integrated azimuth sensor according to the first aspect, the magnetic sensor is on the support body or the weight portion and sandwiches a predetermined center portion thereof. A first magnetic flux concentrator plate that is disposed so as to face the first direction and converges the magnetic flux in the first direction; and a first magnetic flux focusing plate that is on the support or on the weight portion and that sandwiches the central portion. A second magnetic flux concentrator plate that is disposed so as to face a second direction orthogonal to the second direction and that converges the magnetic flux in the second direction; 1
And a Hall element for detecting the magnetic flux spreading in the vicinity of each of the ends of the second magnetic flux concentrator on the side of the center, respectively.

According to a fifth aspect of the present invention, in the integrated azimuth sensor according to the first aspect, the magnetic sensor is on the support or on the weight portion, and is arranged at a predetermined position thereof. A magnetic converging plate having a shape, and a Hall element for detecting a magnetic flux spreading in the vicinity of each end of the magnetic concentrating plate on the surface side of the support or the weight portion, respectively. It is characterized by. According to a sixth aspect of the present invention, in the integrated orientation sensor according to any of the second to fifth aspects, the magnetic flux concentrator plate is composed of a thin plate made of a soft magnetic material. Is.

According to a seventh aspect of the present invention, there is provided the integrated azimuth sensor according to any one of the first to sixth aspects,
The acceleration sensor portion has a support body having a hollow portion in the center and fixed, a weight portion arranged in the hollow portion of the support body, and a wall thickness for movably supporting the weight portion on the support body. And a plurality of thin beams, and the magnetic sensor is arranged on the weight portion. The invention according to claim 8 is the first to sixth aspects.
In the integrated azimuth sensor according to any one of 1, the acceleration sensor unit includes a fixed support member, a weight portion arranged so as to surround the support member, and the weight portion movably attached to the support member. A plurality of thin-walled beams to be supported, and the magnetic sensor is arranged on the weight portion.

According to a ninth aspect of the present invention, in the integrated azimuth sensor according to the seventh or eighth aspect, each of the beams has a piezoresistive element as a stress detecting element at a stress concentration portion at both ends thereof. It is characterized by being present. According to a tenth aspect of the invention, in the integrated orientation sensor according to the seventh or eighth aspect, each of the beams is provided with a MOS transistor as a stress detecting element at a stress concentration portion at both ends thereof. It is what

An eleventh aspect of the present invention is the integrated azimuth sensor according to any one of the first to sixth aspects, wherein the acceleration sensor section is the support, the weight section,
And in addition to the plurality of beams, further comprising a case that is fixed to the support on the upper side of the weight portion and has a space in which the weight portion can move, and a movable electrode is provided at a predetermined position on the surface of the weight portion, It is characterized in that a fixed electrode is provided on the back surface side of the case at a position facing the movable electrode to form a capacitance type acceleration sensor.

According to a twelfth aspect of the present invention, in the integrated azimuth sensor according to the eleventh aspect, the magnetic flux concentrator plate and the movable electrode are made of the same soft magnetic material. According to the present invention having such a configuration, it is possible to realize a small-sized integrated azimuth sensor that can detect an azimuth based on geomagnetism and gravitational acceleration and can be mounted on a mobile device or the like.

Further, in the invention according to the third aspect, since the number of magnetic flux concentrator plates to be arranged can be increased, the magnetic flux converging effect by the magnetic flux concentrator plates can be enhanced and the sensitivity of the magnetic sensor can be enhanced. You can Further, in this case, since the number of arranged Hall elements can be increased, there is an advantage that the output voltage after calculating the output voltage from each Hall element can be increased. Further, according to the invention described in claims 4 and 5, the magnetic flux concentrator plate can be formed in an elongated shape. For this reason, the demagnetizing field coefficient of the magnetic flux concentrator is reduced, the magnetic flux converging effect in the horizontal direction can be enhanced with respect to the substrate on which the magnetic flux concentrator is arranged, and the sensitivity of the magnetic sensor can be enhanced.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (First Embodiment) FIG. 1 is a perspective view showing an external structure of a first embodiment of the present invention, a part of which is cut away. As shown in FIG. 1, the integrated azimuth sensor according to the first embodiment includes a triaxial acceleration sensor 3 that detects gravitational acceleration, at least a triaxial magnetic sensor 4 that detects geomagnetism, and an acceleration sensor 3. The acceleration processing information and the magnetic information from the magnetic sensor 4 are arithmetically processed as described later to obtain an azimuth angle. The arithmetic processing section 6 is a signal processing section.

The acceleration sensor 3 comprises a support 8 fixed to the glass table 5, a weight portion 7, and beams 31 to 38 for movably supporting the weight portion 7 on the support body 8. This configuration will be described later. Further, as shown in FIG. 1, a magnetic sensor 4 and an arithmetic processing unit 6 which are smaller in scale than the acceleration sensor 3 are arranged at predetermined positions on the weight portion 7 constituting the acceleration sensor 3.

As described above, in the azimuth angle sensor according to the first embodiment, the magnetic sensor 4 and the arithmetic processing unit 6 which are smaller in scale than the acceleration sensor 3 are provided in a part of the weight portion 7 constituting the acceleration sensor 3. It is intended to be downsized as a whole. Next, the configuration of the acceleration sensor 3 will be described. Here, the acceleration sensor 3
Is an international publication (International Publication Number: WO00 / 79) that has been internationally applied by the applicant of the present invention and has already been published internationally.
The configuration is the same as that of the acceleration sensor described in 288 A1). Therefore, the configuration and the like will be described below to the extent necessary for the description of the first embodiment.

That is, as shown in FIG. 1, the acceleration sensor 3 is formed on a glass substrate 5, and a weight portion 7 formed of a quadrangular pyramid pyramid and inverted upside down is formed at the center of the glass substrate 5. It is movably arranged. Around the weight portion 7, a support body 8 made of a rectangular frame is arranged at a predetermined interval so as to surround the weight portion 7, and
The support 8 is fixed to the glass substrate 5. The weight portion 7 is movably supported by the support 8 by the thin-walled beams 31 to 38, and the respective beams 31 to 38 are arranged such that the length direction thereof is along each side of the weight portion 7. Has been done.

Support 8, weight 7, and beams 31-38
Is made of a silicon substrate. Beam 3
1, 32 are arranged so that the length direction thereof is along the upper side of the weight portion 7, one end thereof is commonly connected to the central portion of the upper side of the weight portion 7, and the other end thereof is The support 8 is connected in the vicinity of each corner of the inner peripheral portion. Similarly, beams 33, 34, beams 35, 36, and beams 37, 38.
Are arranged so that their length directions are along the left side, the lower side, and the right side of the weight portion 7, respectively, and one end of each beam is commonly connected to the central portion of the corresponding side of the weight portion 7. The other ends thereof are respectively connected to the inner peripheral portion of the support 8 in the vicinity of the corresponding corners.

Therefore, four spaces 39 as shown in FIG. 1 are formed at each of the four corners of the inner peripheral portion of the support 8. At both ends of the beams 31, 32, which are stress concentration parts,
The stress detecting elements 21, 22, 23, 24 are arranged. Similarly, beams 33, 34, beams 35, 36, and beam 3
The stress detecting elements 21 to 24 are arranged at both ends of the wires 7 and 38, respectively. As the stress detecting elements 21 to 24, piezoresistive elements, MOS transistors, etc. are used.

In the acceleration sensor 3 having such a structure, when acceleration acts, an inertial force acts on the weight portion 7 in a direction opposite to the direction of the acceleration, and the stress detecting elements 21 to 21.
Stress is generated in the portion 24. An acceleration vector in a three-dimensional space can be obtained by performing a predetermined calculation using the output signals of the stress detection elements 21 to 24 arranged at 16 places. Since the details of this operation are described in the above-mentioned International Publication, the description thereof is omitted here.

Since gravitational acceleration always acts on the acceleration sensor 3, based on the obtained acceleration vector,
As will be described later, the substrate surface (weight portion 7) with respect to the horizontal surface of the surface.
You can get the slope of. In addition, the stress detection elements 21 to 2
Since No. 4 is formed on the same substrate at the same time, variations in characteristics are small, and the temperature coefficient of sensitivity of the stress detection elements 21 to 24 changes similarly. Therefore, the relative values of the three components of the acceleration vector are constant even if the temperature changes, and the inclination of the substrate surface with respect to the horizontal surface of the surface can be accurately obtained.

Next, details of the structure of the magnetic sensor 4 will be described with reference to FIG. 2A is a plan view of the magnetic sensor 4, and FIG. 2B is a sectional view taken along the line AA of FIG. The magnetic sensor 4 is, as shown in FIG.
It is formed on the surface of the weight portion 7 made of a silicon substrate. That is, the Hall elements 41 to 44 are formed at predetermined four positions on the surface of the weight portion 7. The Hall elements 41 to 44 are formed simultaneously with the arithmetic processing unit 6 by a conventional method for forming a CMOS circuit.

As shown in FIG. 2A, the hall element 41 and the hall element 42 are arranged so as to face each other in the X-axis direction on the surface of the weight portion 7. The Hall element 43 and the Hall element 44 are arranged so as to face each other in the Y-axis direction on the surface of the weight portion 7. Therefore, the arrangement direction of the Hall elements 41 and 42 is orthogonal to the arrangement direction of the Hall elements 43 and 44. Weight 7 and Hall elements 41 to 4
An insulating layer 51 is formed on the surface of the insulating layer 51.
The magnetic flux concentrator 45 is disposed on the surface of the. The magnetic flux concentrator plate 45 is made of, for example, a disc-shaped thin plate made of a soft magnetic material. The magnetic flux concentrator 45 has a Hall element 4 at its center.
1, 42 and the Hall elements 43, 44 are arranged so as to be orthogonal to each other. And the magnetic flux concentrator 4
5 is arranged such that the vicinity of the outer peripheral end of the magnetic flux concentrator plate 45 faces the Hall elements 41 to 44 when arranged.

With such a configuration, the magnetic flux concentrator plate 45
Are designed to converge magnetic flux parallel to the magnetic flux concentrator plate 45. Next, the operation of the magnetic sensor 4 having such a configuration will be described with reference to FIG. First, X
The magnetic flux in the axial direction will be described. As shown in FIG. 2 (B), the magnetic flux Bx in the X-axis direction is converged in the X-axis direction by the magnetic flux concentrator plate 45, but at the end of the magnetic flux concentrator plate 45, the magnetic flux spreads in the Z-axis direction, causing holes. In the elements 41 and 42, the Z-axis direction component of the magnetic flux appears.

At this time, the Hall element 41 and the Hall element 4
Since the Z-axis component of the magnetic flux in 2 is opposite, the magnetic flux density in the X-axis direction can be detected by taking the difference between the output of the Hall element 41 and the output of the Hall element 42. At this time, even if a magnetic flux in the Z-axis direction is applied from the outside,
Since the difference between the output of the hall element 41 and the output of the hall element 42 is calculated, the difference is canceled. Regarding the magnetic flux in the Y-axis direction, even if the magnetic flux is converged by the magnetic flux concentrator 45, the Hall element 41,
At the position of 42, it does not appear as a component in the Z-axis direction.

The magnetic flux density in the Y-axis direction can be detected by the Hall elements 43 and 44 according to the same principle as the magnetic flux density in the X-axis direction. The magnetic flux density in the Z-axis direction is the Hall elements 41 to 4
This can be detected by taking the sum of the outputs of 4 above. At this time, the magnetic flux in the X-axis direction applied from the outside is canceled by taking the sum of the output of the Hall element 41 and the output of the Hall element 42. Similarly, the magnetic flux in the Y-axis direction applied from the outside is canceled by taking the sum of the output of the Hall element 43 and the output of the Hall element 44.

The above description can be expressed as follows using mathematical expressions. That is, the hall elements 41, 42, 43,
44 output voltage to Vh41, Vh42, Vh43, Vh
44, the calculated X-axis direction, Y-axis direction, and Z
The outputs in the axial direction are as follows for Dx, Dy and Dz. Dx = Vh41-Vh42 Dy = Vh43-Vh44 Dz = Vh41 + Vh42 + Vh43 + Vh44 As described above, the magnetic sensor 4 can detect the magnetic flux vector in the three-dimensional space.

The magnetic sensor 4 is composed of a plurality of Hall elements 41 to 44 simultaneously formed on the same silicon substrate. Therefore, the Hall elements 41 to 44 have a small variation in characteristics, and the temperature characteristics of sensitivity also change. Therefore, the relative values of the three components of the geomagnetic vector are constant even if the temperature changes, and the direction of the geomagnetism can be detected with high accuracy. Next, the configuration of the arithmetic processing unit 6 that arithmetically processes the output signal of the acceleration sensor 3 and the output signal of the magnetic sensor 4 configured as described above will be described with reference to the block diagram of FIG.

As shown in FIG. 3, the arithmetic processing unit 6 is
An A / D conversion unit 115, a correction calculation unit 116, a correction value storage unit 117, and an azimuth angle calculation unit 118 are provided, and these are integrated on the weight unit 7 made of a silicon substrate. The A / D converter 115 outputs the output signals Ka, Kb, Kc of the acceleration sensor 3 and the output signals Dx, D of the magnetic sensor 4.
Since y and Dz are analog signals, these analog signals are converted into digital signals (digital values).

The correction value storage unit 117 stores the X value of the magnetic sensor 4.
Offset values Lx, Ly, Lz of the output signals Dx, Dy, Dz of the axis, the Y axis, and the Z axis and the sensitivity ratios Gx, Gy, Gz.
And the offset value M of the X-axis, Y-axis, and Z-axis output signals Ka, Kb, and Kc of the acceleration sensor 3.
It is a memory for storing x, My, Mz and sensitivity ratios Hx, Hy, Hz. As described above, the correction value storage unit 117 stores each correction data by the output signal D of the magnetic sensor 4.
x, Dy, Dz, and the output signal K of the acceleration sensor 3
This is because there is an offset or the like in a, Kb, and Kc and this is to be corrected.

The correction calculation unit 116 includes a correction value storage unit 117.
The offset values Lx, Ly, Lz and the sensitivity ratio G stored in
By using x, Gy, and Gz, the output signals Dx, Dy, and Dz of the magnetic sensor 4 are corrected, only the values α, β, and γ proportional to each axial component of the earth's magnetism are obtained, and these are calculated. It is designed to output to. Further, the correction calculation unit 116 uses the offset values Mx, My, Mz and the sensitivity ratios Hx, Hy, Hz stored in the correction value storage unit 117 to output the output signals Ka, Kb of the acceleration sensor 3.
Kc is corrected, and the biaxial inclinations φ and η with respect to gravity are obtained,
These are output to the azimuth angle calculation unit 118.

The azimuth calculation unit 118 includes a correction calculation unit 116.
The azimuth angle θ is calculated as described below by using the corrected triaxial magnetic field data α, β, γ and the biaxial inclinations φ, η with respect to gravity. Next, in the arithmetic processing unit 6 having such a configuration, the azimuth angle calculation unit 1
An example of the algorithm by which 18 calculates the azimuth angle θ will be described below. Here, in the azimuth angle calculation unit 118, the triaxial geomagnetic data α, β, γ with corrected sensitivity and offset, and the biaxial inclinations φ, η with respect to gravity are
It is assumed that it is input from the correction calculator 116.

FIG. 4 is a diagram showing the relationship between the geomagnetic vector and the rotation axis when the azimuth angle θ is calculated. In FIG. 4, the TMx axis is set corresponding to the geomagnetic vector (x, y, z), and the two axes orthogonal to this TMx axis are TMy axis, T
Let it be the Mz axis. In addition, the mobile terminal 11 according to the first embodiment is used.
When mounted on 0 and used, the azimuth of the mobile terminal 110 with respect to the geomagnetic vector (x, y, z) is θ, and the depression angle is δ. Furthermore, the mobile terminal 110 is assumed to be inclined from the horizontal plane by an angle φ in the longitudinal direction and an angle η in the lateral direction.

Then, in order to correct the depression angle δ, TMy
Rotate -δ around the axis, and rotate the axis after this by H
X, HY, and HZ. Then, around the HZ axis, the angle θ
And rotate the axes after this rotation to M1x, M1y, M1.
z. Next, it is rotated about the M1y axis by −φ, the rotated axes are set to M2x, M2y, and M2z, and further rotated about the M2x axis by −η.

By these rotations, the geomagnetic vector (x, y, z) and the output (α, β,
The following equation (1) is established between (γ).

[0043]

[Equation 1]

Then, the magnetic vector (x, y, z) =
When the output (α, β, γ) from the magnetic sensor is obtained from the relationship of (1, 0, 0), the following equation (2) is obtained.

[0045]

[Equation 2]

Next, by modifying the expression of α in the expression (2), the following expression (3) is obtained.

[0047]

[Equation 3]

Next, by substituting the equation (3) into the equations β and γ in the equation (2), the following equations (4) and (5) are obtained.

[0049]

[Equation 4]

Next, from equations (4) and (5), cos (δ)
By obtaining, the following equation (6) is obtained.

[0051]

[Equation 5]

Next, by transforming the equation (6) to obtain the azimuth angle θ, the following equation (7) is obtained.

[0053]

[Equation 6]

Thus, the triaxial geomagnetic data α, β,
The azimuth angle θ can be calculated without using the depression angle δ by using γ and the biaxial inclination data φ and η with respect to gravity. As described above, in the first embodiment, the magnetic sensor 4 and the arithmetic processing unit 6 are incorporated in a part of the weight portion 7 that constitutes the acceleration sensor 3. Therefore, the size can be reduced as a whole.

Further, in the first embodiment, since the stress detecting elements 21 to 24 are simultaneously formed on the same substrate,
The variation in characteristics is small, and the temperature coefficient of sensitivity of the stress detecting elements 21 to 24 changes similarly. Therefore, the relative values of the three components of the acceleration vector are constant even if the temperature changes, and the inclination of the substrate surface with respect to the horizontal surface of the surface can be accurately obtained. Further, in the first embodiment, the magnetic sensor 4
Is composed of a plurality of Hall elements 41 to 44 which are simultaneously formed on the same silicon substrate. Therefore, the Hall elements 41 to 44 have a small variation in characteristics, and the temperature characteristics of sensitivity also change. Therefore, 3 of the geomagnetic vector
The relative value of the component is constant even if the temperature changes, and the direction of the geomagnetism can be detected with high accuracy.

Furthermore, in this first embodiment, the acceleration vector and the magnetic flux vector do not change when stationary. On the other hand, when moving, the acceleration vector and the magnetic flux vector change. Therefore, this first
When the embodiment is incorporated in a mobile device, a state in which the mobile device is not used, that is, a stationary state can be detected by detecting changes in the acceleration vector and the magnetic flux vector, and an unnecessary electric circuit in the stationary state. The current consumption can be reduced by stopping.

In the first embodiment, the magnetic sensor 4 and the arithmetic processing unit 6 are incorporated in a part of the weight portion 7 which constitutes the acceleration sensor 3. However, the magnetic sensor 4 and the arithmetic processing unit 6 may be arranged on the support 8 forming the acceleration sensor 3, or may be distributed to the weight portion 7 forming the acceleration sensor 3 and the support 8. You may arrange it. Such an idea can be similarly applied to each embodiment described later.

In addition, in the first embodiment, the output signals from the stress detecting elements 21 to 24 and the output signal from the magnetic sensor 4 are supplied to the arithmetic processing unit 6 on the weight portion 7 or the like. Is electrically connected to the
The calculation processing result of the calculation processing unit 6 can be output to the outside. (Second Embodiment) This second embodiment has the same basic configuration as that of the first embodiment, and its magnetic sensor 4 (see FIG.
5) is replaced with a magnetic sensor 4A as shown in FIG. Therefore, only the configuration of the magnetic sensor 4A will be described below.

FIG. 5 is a diagram showing the configuration of the magnetic sensor 4A, FIG. 5 (A) is a plan view of the magnetic sensor 4A, and FIG. 5 (B) is a line BB in FIG. 5 (A). FIG. In this magnetic sensor 4A, as shown in FIG. 5, a magnetic flux concentrating plate 65 made of, for example, a circular thin plate is arranged at a predetermined position on the weight portion 7 made of a silicon substrate. further,
Four magnetic flux concentrating plates 66 to 69, which are, for example, circular thin plates, are arranged around the magnetic flux concentrating plate 65 at a predetermined distance in the outer circumferential direction of the magnetic flux concentrating plate 65. There is. The magnetic flux concentrator plates 65 to 69 are made of, for example, a soft magnetic material.

More specifically, two magnetic flux concentrating plates 66 and 67 are arranged on the right and left sides of the magnetic flux concentrating plate 65 with a predetermined interval, and two magnetic flux concentrating plates 65 are provided before and after the magnetic flux concentrating plate 65 with a predetermined interval. The magnetic flux concentrator plates 68 and 69 are arranged. Therefore, the magnetic flux concentrator plates 67, 65, 66 are arranged in the X-axis direction at a predetermined interval, and the magnetic flux concentrator plates 68, 65,
69 are arranged at a predetermined interval in the Y-axis direction. In the surface area of the weight portion 7, the magnetic flux concentrating plate 65 and the magnetic flux concentrating plates 66, 67, 68 and 69 are adjacent to each other, and the magnetic flux concentrating plate 65 and the magnetic flux concentrating plates 66, 67, 68 and 6 are adjacent to each other.
The Hall element 61 is provided on the lower side of each end portion where 9 are opposed to each other.
a, 61b, 62a, 62b, 63a, 63b, 64
a and 64b are arranged respectively.

That is, as shown in FIG. 5, at the positions of the end portions where the magnetic flux concentrating plate 65 and the magnetic flux concentrating plate 66 face each other, and on the surface of the weight portion 7 near the lower side of the position, holes are formed. Elements 61a and 61b are arranged. Hall elements 62a and 62b are arranged on the surface of the weight portion 7 at the positions of the end portions where the magnetic flux concentrator plate 65 and the magnetic flux concentrator plate 67 face each other and below the positions. Therefore, the arrangement direction of the Hall elements 61a, 61b, 62a, 62b is
It is in the X-axis direction.

Further, the magnetic flux concentrator plate 65 and the magnetic flux concentrator plate 68.
Hall elements 63a and 63b are arranged on the surface of the weight portion 7 near the lower sides of the positions where and are opposed to each other. Further, the magnetic flux concentrator 65 and the magnetic flux concentrator 6
Hall elements 64a and 64b are provided on the surface of the weight portion 7 near the lower side of the positions at which the respective ends face each other.
Are arranged. Therefore, the Hall elements 63a, 63
The arrangement direction of b, 64a, and 64b is the Y-axis direction.

Next, the operation of the magnetic sensor 4A having such a configuration will be described with reference to FIG. Now
When a magnetic field is applied from the outside in the X-axis direction, the magnetic flux is converged by the magnetic flux concentrator plates 67, 65, 66. There are gaps in the converged magnetic flux between the magnetic flux concentrator plate 65 and the magnetic flux concentrator plate 67 and between the magnetic flux concentrator plate 65 and the magnetic flux concentrator plate 66. Therefore, the converged magnetic flux spreads in the Z-axis direction in the area of the gap as shown in FIG. 5 (B).

At this time, the components of the magnetic flux in the Z-axis direction are the same in the Hall elements 61a and 62b, whereas those in the Hall elements 61b and 62a are the Hall elements 61a and 62b.
It is the same in the opposite direction as b. Therefore, the hall element 61a
X and the output voltage of the Hall element 62b, and the sum of the output voltage of the Hall element 61b and the output voltage of the Hall element 62a, and by taking the difference between them, X
The magnetic flux density in the axial direction can be obtained.

With respect to the external magnetic field in the Y-axis direction, Z is at the positions of the Hall elements 61a, 61b, 62a and 62b.
No axial component appears. With respect to the external magnetic field in the Z-axis direction, the output voltages of the Hall elements 61a, 61b, 62a, 62b are all the same and do not appear in the output in the X-axis direction after the calculation. The Hall element 63 is used to detect the magnetic flux density in the Y-axis direction.
The output voltage of a, 63b, 64a, 64b can be calculated by the same calculation as in the X-axis direction.

The magnetic flux density in the Z-axis direction is detected by all the Hall elements 61a, 61b, 62a, 62b, 63a, 63.
This is done by taking the sum of the output voltages of b, 64a and 64b. At this time, the output voltage of the pair of Hall elements such as the Hall elements 61a and 61b is opposite to the external magnetic field in the X-axis direction and the Y-axis direction. Becomes The above description can be expressed as follows using mathematical expressions.

That is, the hall elements 61a, 61b, 6
The output voltages of 2a, 62b, 63a, 63b, 64a and 64b are Vh61a, Vh61b, Vh62a and Vh62.
b, Vh63a, Vh63b, Vh64a, Vh64b
Then, the outputs in the X-axis direction, the Y-axis direction, and the Z-axis direction after the calculation are as follows for Dx, Dy, and Dz. Dx = Vh61a-Vh61b-Vh62a + Vh62
b Dy = Vh63a-Vh63b-Vh64a + Vh64
b Dz = Vh61a + Vh61b + Vh62a + Vh62
b + Vh63a + Vh63b + Vh64a + Vh64b As described above, the magnetic sensor 4A according to the second embodiment is
As compared with the magnetic sensor 4 of the first embodiment, as shown in FIG. 5, the number of arranged magnetic flux concentrator plates can be increased. Therefore, the magnetic flux converging effect of the magnetic converging plate can be enhanced,
The sensitivity of the magnetic sensor can be increased.

Further, in this case, since the number of arranged hall elements constituting the magnetic sensor 4A can be increased, there is an advantage that the output voltage from each hall element can be increased after the calculation. . Although the magnetic sensor 4A is used by being incorporated in a part of the acceleration sensor 3, it may be independently configured and used for general purpose. The same applies to the magnetic sensor described later. (Third Embodiment) This third embodiment has the same basic configuration as that of the first embodiment, and its magnetic sensor 4 (see FIG.
(See) is replaced with a magnetic sensor 4B as shown in FIG. Therefore, only the configuration of the magnetic sensor 4B will be described below.

FIG. 6 is a diagram showing the structure of the magnetic sensor 4B, FIG. 6 (A) is a plan view of the magnetic sensor 4B, and FIG. 6 (B) is a line CC of FIG. 6 (A). FIG. As shown in FIG. 6, the magnetic sensor 4B has a center portion 80 of a predetermined size provided at a predetermined position on the weight portion 7 made of a silicon substrate, and the center portions 80 are provided on the left and right sides of the center portion 80.
The magnetic flux concentrating plate 76 and the magnetic flux concentrating plate 77 are arranged with the central portion 80 sandwiched therebetween, and the magnetic flux concentrating plate 78 and the magnetic flux concentrating plate 79 are disposed with the central portion 80 sandwiched therebetween. .

That is, the magnetic flux concentrator 76 and the magnetic flux concentrator 7
7 are arranged so as to face each other in the X-axis direction with the central portion 80 sandwiched therebetween. Further, the magnetic flux concentrating plate 78 and the magnetic flux concentrating plate 79
Are arranged to face each other in the Y-axis direction with the central portion 80 interposed therebetween. The magnetic flux concentrator plates 76 to 79 are arranged on the weight portion 7 with the insulating layer 51 interposed therebetween. As shown in FIG. 6, in the surface area of the weight portion 7, the magnetic flux concentrator plates 76 to
Hall elements 71 to 74 are arranged in the vicinity of the respective ends on the side of the central portion 80 of 79 and on the lower side thereof.

Next, the operation of the magnetic sensor 4B having such a configuration will be described with reference to FIG. Now
When a magnetic field is applied from the outside in the X-axis direction, the magnetic flux is converged by the magnetic flux concentrator plates 76 and 77. The magnetic flux thus converged has a gap between the magnetic flux concentrator plate 76 and the magnetic flux concentrator plate 77. Therefore, the converged magnetic flux spreads in the Z-axis direction in the area of the gap as shown in FIG. 6 (B).

At this time, the components of the magnetic flux in the Z-axis direction are opposite in the Hall element 71 and the Hall element 72. Therefore, the magnetic flux density in the X-axis direction can be obtained by taking the difference between the output voltage of the Hall element 71 and the output voltage of the Hall element 72. At this time, with respect to the external magnetic field in the Y-axis direction, Z at the positions of the Hall elements 71 and 72.
No axis component appears. The output voltages of the Hall elements 71, 72, 73, and 74 are all the same with respect to the external magnetic field in the Z-axis direction, and do not appear in the output in the X-axis direction after the calculation.

The magnetic flux density in the Y-axis direction can be detected by calculating the output voltages of the Hall elements 73 and 74 in the same manner as in the X-axis direction. The magnetic flux density in the Z-axis direction is detected by taking the sum of the output voltages of all the Hall elements 71 to 74. At this time, with respect to the external magnetic field in the X-axis direction and the Y-axis direction, the outputs of the Hall element 71 and the Hall element 72 and the Hall element 73 and the Hall element 74 are in the opposite directions, and the sum of these is obtained. The output will be zero.

The above description can be expressed as follows using mathematical expressions. That is, the Hall elements 71, 72, 73,
The output voltage of 74 is Vh71, Vh72, Vh73, Vh
74, the calculated X-axis direction, Y-axis direction, and Z
The outputs in the axial direction are as follows for Dx, Dy and Dz. Dx = Vh71-Vh72 Dy = Vh73-Vh74 Dz = Vh71 + Vh72 + Vh73 + Vh74 As described above, in the magnetic sensor 4B of the third embodiment, the magnetic flux concentrator plates 76 to 79 are elongated, so that the diamagnetic field coefficient of the magnetic flux concentrator plate is large. It becomes smaller and enhances the magnetic flux convergence effect in the horizontal direction with respect to the substrate on which the magnetic flux concentrator is placed.
The sensitivity of the magnetic sensor can be increased. (Fourth Embodiment) This fourth embodiment has the same basic configuration as that of the first embodiment, and its magnetic sensor 4 (see FIG.
(See) is replaced with a magnetic sensor 4C as shown in FIG. Therefore, only the configuration of the magnetic sensor 4C will be described below.

FIG. 7 is a diagram showing the structure of the magnetic sensor 4C, FIG. 7 (A) is a plan view of the magnetic sensor 4C, and FIG. 7 (B) is a line D--D in FIG. 7 (A). FIG. In this magnetic sensor 4C, as shown in FIG. 7, a magnetic flux concentrator plate 85 made of a soft magnetic material having a cross shape is arranged at a predetermined position on the weight portion 7 made of a silicon substrate. The magnetic flux concentrator plate 85 is made of a thin plate as a whole, and
The axial part and the Y-axis part are orthogonal to each other. The magnetic flux concentrator plates 85 are arranged on the weight portion 7 with the insulating layer 51 interposed therebetween.

As shown in FIG. 7, in the surface area of the weight portion 7, in the vicinity of each end portion of each portion of the magnetic flux concentrator plate 85 in the X-axis direction and the Y-axis direction, and on each lower side thereof. , Hall elements 81 to 84 are respectively arranged. Next, the operation of the magnetic sensor 4C having such a configuration will be described with reference to FIG. Now, when a magnetic field is applied from the outside in the X-axis direction, the magnetic flux is converged by the portion of the magnetic flux concentrator plate 85 in the X-axis direction. As shown in FIG. 7B, the converged magnetic flux spreads in the Z-axis direction at the end portion of the X-axis direction portion of the magnetic flux concentrator plate 85.

At this time, the components of the magnetic flux in the Z-axis direction are opposite in the Hall element 81 and the Hall element 82. Therefore, the magnetic flux density in the X-axis direction can be obtained by taking the difference between the output voltage of the Hall element 81 and the output voltage of the Hall element 82. At this time, with respect to the external magnetic field in the Y-axis direction, Z at the positions of the Hall elements 81 and 82.
No axis component appears. With respect to the external magnetic field in the Z-axis direction, the output voltages of the Hall elements 81, 82, 83, 84 are all the same and do not appear in the output in the X-axis direction after the calculation.

The magnetic flux density in the Y-axis direction can be detected by calculating the output voltages of the Hall elements 83 and 84 in the same manner as in the X-axis direction. The magnetic flux density in the Z-axis direction is detected by taking the sum of the output voltages of all the Hall elements 81-84. At this time, with respect to the external magnetic fields in the X-axis direction and the Y-axis direction, the outputs of the hall element 81 and the hall element 82 and the hall element 83 and the hall element 84 are in opposite directions. The output will be zero.

The above description can be expressed as follows using mathematical expressions. That is, the hall elements 81, 82, 83,
The output voltage of 84 is Vh81, Vh82, Vh83, Vh
84, the X-axis direction, Y-axis direction, and Z after calculation
The outputs in the axial direction are as follows for Dx, Dy and Dz. Dx = Vh81-Vh82 Dy = Vh83-Vh84 Dz = Vh81 + Vh82 + Vh83 + Vh84 (Fifth Embodiment) In the fifth embodiment, the acceleration sensor 3 of the first embodiment is replaced by an acceleration sensor 3A as shown in FIG.
Is replaced with.

The acceleration sensor 3A, as shown in FIG.
The support 1 is arranged in the center, and the weight portion 2 is arranged around the support 1. That is, the support 1 is arranged at the position of the weight 7 of the acceleration sensor 3 shown in FIG. 1, the weight 2 is arranged at the position of the support 8 of the acceleration sensor 3, and the arrangement is replaced. Is. The acceleration sensor 3A is a glass table 5
The supporting member 1 is fixed to the supporting member 1, the weight portion 2, and the beams 11 to 18 that movably support the weight portion 2 on the supporting member 1 and the like. This configuration will be described later.

Further, at a predetermined position on the weight portion 2 and the predetermined position on the support body 1 constituting the acceleration sensor 3A, a magnetic sensor 4 and an arithmetic processing unit 6 which are smaller in scale than the acceleration sensor 3A are provided. It is distributed and arranged. As described above, in the azimuth sensor according to the fifth embodiment, the magnetic sensor 4 having a smaller scale than the acceleration sensor 3A is provided in a part of the weight portion 2 and a part of the support body 1 forming the acceleration sensor 3A. The arithmetic processing section 6 and the arithmetic processing section 6 are respectively incorporated so as to reduce the size as a whole.

Next, the structure of the acceleration sensor 3A will be described. Here, the acceleration sensor 3A has the same configuration as the acceleration sensor described in the above-mentioned International Publication. Therefore, in the following, description will be given within the range necessary for the description of the fifth embodiment. That is, as shown in FIG. 8, this acceleration sensor 3A is formed on a glass substrate 5, and a support 1 made of a truncated quadrangular pyramid and having its inverted shape is fixed to the center of the glass substrate 5. There is. Around this support 1,
A weight portion 2 formed of a rectangular frame is arranged at a predetermined interval so as to surround the support 1.

The weight portion 2 is movably supported by the support 1 by the thin beams 11 to 18, and the length direction of each of the beams 11 to 18 is along each side of the support 1. Are arranged as follows. Support 1, weight 2, and beam 1
1 to 18 are formed by using a silicon substrate as a material. As shown in the drawing, the beams 11 and 12 are arranged such that their lengthwise directions are along the upper side of the support 1, and one ends thereof are commonly connected to the central portion of the upper side of the support 1 and the other ends thereof. Are respectively connected to the corners (corner portions) of the inner peripheral portion of the weight portion 2.

Similarly, the beams 13 and 14, the beams 15 and 16, and the beams 17 and 18 are arranged so that their length directions are along the left side, the lower side, and the right side of the support 1, respectively, as shown in the drawing. One end of each beam is commonly connected to the central portion of the corresponding side of the support 1, and the other end thereof is connected to the corresponding corner portion of the inner peripheral portion of the weight portion 2. Beams 11, 1
The stress detecting elements 21, 2
2, 23, 24 are arranged. Similarly, the beams 13, 1
4, each of the beams 15, 16 and the beams 17, 18 has
The stress detecting elements 21 to 24 are arranged respectively. As the stress detecting elements 21 to 24, piezoresistive elements, MO
An S transistor or the like is used.

Acceleration sensor 3A having such a configuration
Then, when acceleration acts, an inertial force acts on the weight portion 2 in a direction opposite to the direction of the acceleration, and the stress detecting element 21
The stress is generated in the part of ~ 24. An acceleration vector in a three-dimensional space can be obtained by performing a predetermined calculation using the output signals of the stress detection elements 21 to 24 arranged at 16 places. Since the details of this operation are described in the above-mentioned International Publication, the description thereof is omitted here.

In the fifth embodiment, the output signal of the acceleration sensor 3A is the same as the output signal of the acceleration sensor 3 of the first embodiment, and the magnetic sensor 4 has the same structure as that of the first embodiment. Therefore, the output signal of the acceleration sensor 3A and the output signal of the magnetic sensor 4 can be processed by the calculation processing unit 6 shown in FIG. 3 in the same manner as in the first embodiment. In addition, in the fifth embodiment, the magnetic sensor 4
May be replaced with the other magnetic sensors 4A, 4B, and 4C described above.

In the fifth embodiment, as shown in FIG. 8, the magnetic sensor 4 and the signal processing section 6 are arranged in the weight section 2 and the support 1 in a dispersed manner. However, the magnetic sensor 4 and the signal processing unit 6 may be arranged on either the weight 2 or the support 1. (Sixth Embodiment) FIG. 9 is a perspective view of the sixth embodiment with a cover removed, and FIG. 10 is a sectional view of the center of FIG. 9 with a cover attached. .

In the sixth embodiment, the acceleration sensor 3 of the first embodiment (see FIG. 1) is replaced with a capacitance type acceleration sensor 3B as shown in FIGS. 9 and 10. The acceleration sensor 3B includes a support 93 fixed on the glass base 91, a weight portion 92, beams 101 to 108 for movably supporting the weight portion 92 on the support 93, a cover 94, movable electrodes 95 to 98, and Fixed electrode 125, 1
26 and the like as will be described later. Furthermore, the magnetic sensor 4 and the arithmetic processing unit 6 are provided at a predetermined position on the weight portion 92 and a predetermined position on the support body 93 that form the acceleration sensor 3B.
And are distributed.

As described above, in the azimuth angle sensor according to the sixth embodiment, the magnetic sensor 4 and the arithmetic processing unit 6 are provided in a part of the weight portion 92 and a part of the support body 93 constituting the acceleration sensor 3B. Each of them is built in to reduce the size as a whole. Next, the configuration of the acceleration sensor 3B will be described. As shown in FIGS. 9 and 10, the acceleration sensor 3B is formed on a glass substrate 91, and a weight portion 92 made up of a truncated pyramid and having an inverted shape is movable in the center of the glass substrate 91. It is located in.

Around the weight portion 92, a support 93 made of a quadrangular frame is arranged at a predetermined interval, and the support portion 93 has the weight portion 92.
The support 93 is fixed to the glass substrate 91. The weight portion 92 is movably supported by the support body 93 by the thin-walled beams 101 to 108, and the respective beams 101 to 108 are arranged such that the length direction thereof is along each side of the weight portion 92. Has been done. Support 93, weight 92, and beams 101-108
Is made of a silicon substrate.

As shown in the figure, the beams 101 and 102 are arranged so that the length direction thereof is along the upper side of the weight portion 92, and one end of each of them is commonly connected to the central portion of the upper side of the weight portion 92. Each of the other ends is connected to the vicinity of the corner of the inner peripheral portion of the support 93. Similarly, the beams 103 and 104, the beams 105 and 106, and the beams 107 and 108 are arranged so that their length directions are along the left side, the lower side, and the right side of the weight portion 92, respectively, as shown in the drawing. One end of the beam is commonly connected to the central portion of the corresponding side of the weight portion 92, and the other end thereof is connected to the vicinity of the corresponding corner portion of the inner peripheral portion of the support body 93, respectively.

Therefore, four spaces 109 as shown in FIG. 9 are formed at each of the four corners of the inner peripheral portion of the support 93. As shown in FIG. 9, movable electrodes 95, 9 for forming capacitors are provided at four corners on the weight portion 92.
6, 97 and 98 are arranged respectively. In addition, a magnetic flux concentrator plate 45 that constitutes the magnetic sensor 4 is arranged in the center of the weight portion 92. The movable electrodes 95 to 98 and the magnetic flux concentrator plate 45 are thin plates made of the same soft magnetic material.

As shown in FIG. 10, a cover 94 made of a silicon substrate is provided on the support 93. Then, the back surface side (inside) of the cover 94 and the upper surface side of the weight portion 92 face each other. Further, the cover 94 has a space on the back surface side thereof in which the weight portion 92 can move. Further, on the back surface side (inner side) of the cover 94, at a position facing the movable electrodes 95 and 96 on the weight portion 92, a fixed electrode 125 for forming a capacitor between the movable electrodes 95 and 96. , 126 are arranged respectively. Similarly, two fixed electrodes (not shown) for forming a capacitor between the movable electrodes 97 and 98 are provided on the back surface side of the cover 94 at positions facing the movable electrodes 97 and 98. Each is arranged.

Next, the principle of obtaining the accelerations in the X-axis direction, the Y-axis direction and the Z-axis direction by the acceleration sensor 3B will be described with reference to FIGS. 9 to 11. When acceleration acts on the acceleration sensor 3B, an inertial force acts on the weight portion 92 in a direction opposite to the acceleration, and the position of the weight portion 92 changes with respect to the cover 94. Now
Let Cx1 be the capacitance of the capacitor composed of the movable electrode 96 and the fixed electrode 126, and Cx2 be the capacitance of the capacitor composed of the movable electrode 97 and the corresponding fixed electrode (not shown). Furthermore, the movable electrode 95 and the fixed electrode 1
The electrostatic capacity of the capacitor composed of 25 is Cy1, and the electrostatic capacity of the capacitor composed of the movable electrode 98 and a fixed electrode (not shown) corresponding thereto is Cy2.

These capacitances are converted into voltage by a capacitance-voltage converter, and based on the converted voltage, in the X-axis direction, Y
The acceleration in the axial direction and the acceleration in the Z-axis direction are obtained respectively. That is, when acceleration is applied in the X-axis direction in FIG. 11, the weight portion 7 tilts according to the acceleration, the electrostatic capacitance Cx1 increases, and the electrostatic capacitance Cx2 decreases. Therefore, the first acceleration detection circuit (not shown) for obtaining the acceleration in the X-axis direction has the electrostatic capacitance Cx1 and the electrostatic capacitance Cx.
The acceleration signal in the X-axis direction is obtained by taking the difference from 2.

At this time, when acceleration in the Y-axis direction or the Z-axis direction is applied, the electrostatic capacitance Cx1 and the electrostatic capacitance Cx are obtained.
The change amounts of 2 are the same, and the acceleration signal is not output from the first acceleration detection circuit that takes the difference between them. Similarly, the second acceleration detection circuit (not shown) for obtaining the acceleration in the Y-axis direction obtains the acceleration signal in the Y-axis direction by taking the difference between the capacitance Cy1 and the capacitance Cy2. Has become.

The third acceleration detecting circuit (not shown) for obtaining the acceleration in the Z-axis direction has electrostatic capacitances Cx1 and Cx.
An acceleration signal in the Z-axis direction is obtained by taking the sum of 2, Cy1 and Cy2. In the sixth embodiment, the output signal of the acceleration sensor 3B is substantially the same as the output signal of the acceleration sensor 3 of the first embodiment,
The magnetic sensor 4 is configured similarly to the first embodiment. Therefore, the output signal of the acceleration sensor 3B and the output signal of the magnetic sensor 4 can be processed by the calculation processing unit 6 shown in FIG. 3 in the same manner as in the first embodiment.

Further, in the sixth embodiment, the magnetic sensor 4 may be replaced with the above-mentioned other magnetic sensors 4A, 4B, 4C.

[0099]

As described above, according to the present invention,
It is possible to detect an azimuth based on geomagnetism and gravitational acceleration, and it is possible to realize a small-sized and low-cost integrated azimuth sensor that can be mounted on a mobile device or the like. Further, in the present invention, when the number of arranged magnetic flux concentrator plates is increased, the magnetic flux converging effect of the magnetic flux concentrator plates can be enhanced, and the sensitivity of the magnetic sensor can be enhanced. In this case, it is possible to increase the number of arranged Hall elements that form the magnetic sensor, so that there is an advantage that the output voltage from each Hall element can be increased after the calculation.

Furthermore, in the present invention, when the magnetic flux concentrating plate has an elongated shape, the demagnetizing field coefficient of the magnetic flux concentrating plate becomes small and the magnetic flux converging in the horizontal direction with respect to the substrate on which the magnetic flux concentrating plate is arranged. The effect can be enhanced and the sensitivity of the magnetic sensor can be enhanced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external configuration of a first embodiment of an integrated orientation sensor of the present invention.

2A and 2B are diagrams showing a configuration of a magnetic sensor mounted in the first embodiment, FIG. 2A is a plan view thereof, and FIG. 2B is a sectional view taken along line AA of FIG.

FIG. 3 is a block diagram showing a configuration of an arithmetic processing unit in the first embodiment.

FIG. 4 is a diagram showing a relationship between a geomagnetic vector and a rotation axis in the first embodiment.

5A and 5B are diagrams showing a configuration of a magnetic sensor according to a second embodiment, FIG. 5A is a plan view thereof, and FIG. 5B is a cross-sectional view taken along line BB of FIG.

6A and 6B are diagrams showing a configuration of a magnetic sensor according to a third embodiment, FIG. 6A is a plan view thereof, and FIG. 6B is a sectional view taken along line CC of FIG.

7A and 7B are diagrams showing a configuration of a magnetic sensor according to a fourth embodiment, FIG. 7A is a plan view thereof, and FIG. 7B is a sectional view taken along line DD of FIG.

FIG. 8 is a perspective view showing an external configuration of a fifth embodiment of the integrated orientation sensor of the present invention.

FIG. 9 is a perspective view of the integrated azimuth sensor according to a sixth embodiment of the present invention, showing an external configuration thereof, with a cover removed.

FIG. 10 is a sectional view of the center of FIG. 9 with a cover attached.

FIG. 11 is a plan view of FIG.

[Explanation of symbols]

1,8,93 Support 2, 7, 92 Weight section 3, 3A, 3B acceleration sensor 4, 4A-4C magnetic sensor 5,91 glass stand 6 Arithmetic processing unit (signal processing unit) 11-18 beams 21-24 Stress detection element 31-38 beams 41-44 Hall element 45 Magnetic flux concentrator 65-69 Magnetic flux concentrator 61a, 61b, 62a, 62b Hall element 63a, 63b, 64a, 64b Hall element 76 to 79 Magnetic flux concentrator 71-74 Hall element 85 Magnetic flux concentrator 81-84 Hall element 94 cover 95-98 movable electrode 101-108 beams 125,126 Fixed electrode 115 A / D converter 116 Correction calculator 117 Correction value storage unit 118 Azimuth calculator

Claims (12)

[Claims] 1. A magnetic sensor of at least three axes for detecting geomagnetism, an acceleration sensor of two or more axes for detecting gravitational acceleration, a signal processing for processing an output signal from the magnetic sensor and an output signal from the acceleration sensor. The acceleration sensor includes at least a supporting body made of a silicon substrate, a weight portion made of a silicon substrate, and a beam movably supporting the weight portion on the supporting body. The magnetic sensor and the signal processing unit are arranged on either one of the support and the weight portion, or dispersedly arranged on the support and the weight portion. Direction sensor. 2. The magnetic sensor is disposed at a predetermined position on the support or on the weight portion, and the magnetic sensor converges a magnetic flux in a direction along a surface of the support or the weight portion. At least three Hall elements, which are arranged on the front surface side of the body or the weight portion and near the predetermined ends of the magnetic flux concentrator, and which detect the magnetic flux spreading near the respective ends, respectively. The integrated orientation sensor according to claim 1, wherein: 3. The magnetic sensor is provided on the support or the weight portion, and a first magnetic flux concentrator plate arranged at a predetermined position thereof, and on the support or the weight portion. A plurality of second magnetic flux concentrator plates arranged at predetermined intervals in the outer circumferential direction around the first magnetic flux concentrator plate, and on the front surface side of the support or the weight portion, 2. A plurality of Hall elements, each of which detects a magnetic flux spreading near the magnetic converging plate and each of the second magnetic converging plates adjacent to each other, are provided in each vicinity. Integrated orientation sensor. 4. The magnetic sensor is arranged on the support or on the weight portion so as to face each other in a first direction with a predetermined center portion of the magnetic sensor interposed therebetween, and to generate a magnetic flux in the first direction. A first magnetic flux converging plate that converges; and a first magnetic flux concentrator that is disposed on the support or on the weight portion and is opposed to a second direction across the central portion, the second direction being orthogonal to the first direction. A second magnetic flux converging plate for converging magnetic flux in the direction of, and near each end of the first or second magnetic flux concentrating plate on the surface side of the support or the weight portion. The integrated azimuth sensor according to claim 1, further comprising: a Hall element that detects a magnetic flux spreading in the vicinity of the Hall element. 5. The magnetic sensor comprises a cross-shaped magnetic flux concentrator plate disposed on a predetermined position of the support body or the weight portion, and a surface side of the support body or the weight portion. 2. The integrated azimuth sensor according to claim 1, further comprising: a Hall element near each end of the magnetic flux concentrator, each Hall element detecting a magnetic flux spreading in the vicinity thereof. 6. The integrated azimuth sensor according to claim 2, wherein the magnetic flux concentrator is a thin plate made of a soft magnetic material. 7. The acceleration sensor portion has a support body having a hollow portion in the center and fixed, a weight portion arranged in the hollow portion of the support body, and the support portion movably supporting the weight portion. 7. A plurality of thin-walled beams to be supported by the magnetic field sensor, the magnetic sensor being arranged on the weight portion, the integrated structure according to any one of claims 1 to 6. Direction sensor. 8. The acceleration sensor section includes a fixed support body, a weight section arranged so as to surround the support body, and a plurality of thin-walled members for movably supporting the weight section on the support body. 7. The integrated orientation sensor according to claim 1, wherein the magnetic sensor is arranged on the weight portion. 9. The integrated azimuth sensor according to claim 7, wherein each of the beams is provided with a piezoresistive element as a stress detecting element at a stress concentration portion at both ends thereof. 10. The integrated azimuth sensor according to claim 7, wherein each of the beams is provided with a MOS transistor as a stress detecting element in a stress concentration portion at both ends thereof. 11. The acceleration sensor section includes, in addition to the support body, the weight section, and the plurality of beams,
A case, which is fixed to the support body above the weight portion and has a space in which the weight portion can move, further includes a movable electrode provided at a predetermined position on the front surface of the weight portion, and the back side of the case is 7. The integrated azimuth sensor according to claim 1, wherein a fixed electrode is provided at a position facing the movable electrode to form a capacitance type acceleration sensor. 12. The integrated orientation sensor according to claim 11, wherein the magnetic flux concentrator and the movable electrode are made of the same soft magnetic material.